Industry and regulatory agencies are both in need of an improved test to characterize the mutagenic potential of drugs and chemicals. The present in vitro assays detect specific subtypes of DNA damage (i.e., insertions and deletions) of single-copy genes but do not detect mutation that may result during complex cellular processes such as homologous recombination and chromosome segregation. To address these and other limitations of the current mutagenicity screens, the investigator's group has conceptualized an in vitro test for somatic gene mutagenicity using a human erythroleukocyte cell line, a test is based on the widely used in vivo glycophorin A somatic cell mutation assay. This proposed assay would be able to detect mutagens based on their ability to induce the inactivation of an allele of a somatic gene. If developed to its full potential, this assay will complement the mutagenicity assays to screen drug formulations, chemicals and consumer products for human mutagens. This assay can be conducted in a high throughput format permitting the rapid screening of numerous compounds. PROPOSED COMMERCIAL APPLICATION: MB Research will offer this mutagenicity assay to the pharmaceutical, biotech, cosmetic, chemical and consumer products industries. Clients frequently make inquiries concerning alternatives to the Salmonella assay (Ames Test) and CHO/HGPRT mutagenicity assay. The proposed assay will have the ability to detect human mutagens that may be missed by the mutagenicity assays currently available. Since the proposed assay will satisfy an existing demand in the contract-testing industry for a test to detect specific types of human mutagens, the assay has tremendous commercial value.